1. Field of the Invention
The present invention relates to an image processing apparatus which can color correct the color data of an original image and can monitor the result of the color correction.
2. Related Background Art
FIG. 8 shows an example of such a kind of apparatus which has conventionally been known. In the apparatus shown in this diagram, an original such as photograph or the like is wound around a transmission drum 1 and this drum is rotated by a motor 28. A signal which is generated from a quartz oscillator 6 is frequency divided by a frequency divider 26 and the resultant signal is supplied to a motor driving portion 27 to drive the motor 28.
Switches SW.sub.42, SW.sub.43 and SW.sub.44 are closed when the masking process is executed. First, in the case of transmitting a chrominance signal of cyan print, a switch SW.sub.40 is connected to the C side. A light source 2 and a photoelectric converting portion 3 are moved every rotation of the transmission drum 1, thereby obtaining electric signals S.sub.1, S.sub.2 and S.sub.3 corresponding to the original image. Namely, in the photoelectric converting portion 3, the light transmitted through R, G and B color filters so enters the respective photo-sensing portions and is converted into the electric signals S.sub.1, S.sub.2 and S.sub.3, respectively.
The electric signal S.sub.2 and S.sub.3 are supplied to amplifiers 32 and 34 and converted into signals S.sub.2 ' and S.sub.3 ', respectively. The levels of the signals S.sub.2 ' and S.sub.3 ' are adjusted by variable resistors R.sub.12 and R.sub.13 and supplied to an adder 31. The electric signal S.sub.1 is also transmitted to the adder 31.
Thus, the C (cyan) signal is sent from the adder 31 and led to a modulating portion 8 through the switch SW.sub.40. Thus, the amplitude or frequency modulated signal is amplified by an image amplifying portion 10 and output to a transmission line 11. The signal which is output to the transmission line 11 is also supplied to an amplifier 12 and amplified and supplied to a monitor speaker 13. Thus, an audible sound is generated from the speaker 13 to permit personnel thereby to monitor the transmitting state.
In the adder 31, the following operational processes are eventually performed in order to make the photoelectrically converted electric signals S.sub.1 to S.sub.3 adaptive to the ink characteristics for makeup on the reception side: EQU C=S.sub.1 +C.sub.12 .multidot.S.sub.2 '+C.sub.13 .multidot.S.sub.3 '
where C.sub.12 is a coefficient to adjust the level of the signal S.sub.2 ' by means of the variable resistor R.sub.12 and C.sub.13 is a coefficient to adjust the level of the signal S.sub.3 ' by means of the variable resistor R.sub.13.
Substantially similar processes are also executed with regard to magenta print and yellow print and the resultant signals are transmitted to the transmission line 11. Namely, in an adder 33 of a masking operation circuit 36, the following operational process is executed in the case of magenta print: EQU M=C.sub.21 .multidot.S.sub.1 '+S.sub.2 +C.sub.23 .multidot.S.sub.3 '
where, C.sub.21 is a coefficient to adjust the level of the signal S.sub.1 ' by means of a variable resistor R.sub.21 and C.sub.23 is a coefficient to adjust the level of the signal S.sub.3 ' by means of a variable resistor R.sub.23.
In the case of yellow print, the following operational process is executed: EQU Y=C.sub.31 .multidot.S.sub.1 '+C.sub.32 .multidot.S.sub.2 '+S.sub.3
where C.sub.31 is a coefficient to adjust the level of the signal S.sub.1 ' by means of a variable resistor R.sub.31 and C.sub.32 is a coefficient to adjust the level of the signal S.sub.2 ' by means of a variable resistor R.sub.32.
FIG. 9 is an overall constitutional diagram of another still image transmitting apparatus (color photograph transmitting apparatus) which has been conventionally known. In this apparatus, image data output from a television camera or image scanner or the like is first input to an image input portion 50 and color separated into analog chrominance signals of red (R), green (G) and blue (B). The analog signals R, G and B are digitized by an A/D converting portion 51 synchronously with a sampling signal which is generated from a sampling pulse generator 52 and stored in a frame memory 67, respectively. The content of the frame memory 67 is supplied to a D/A converter 56 under control of a high speed read/write (R/W) address setting circuit 53. The converted analog signal is supplied to a monitor 57.
On the other hand, the image data stored in the frame memory 67 is sequentially read out of the addresses designated by a read-out address setting circuit 54 synchronously with timing pulses which are generated from a transmission synchronizing signal generator 55. The read-out digital data is color corrected by a masking operation circuit 59 and input to a modulator (not shown) through a D/A converter 60. The amplitude or frequency modulated signal is transmitted to a transmission line through an amplifier (not shown). The foregoing masking processes are performed on the basis of the table reference system using the input signals R, G and B as addresses. Therefore, a table memory having a large memory capacity is provided in the masking operation circuit 59.
However, since a number of variable resistors are included in the masking operation circuit 36 in the apparatus shown in FIG. 8, there are the drawbacks that it is fairly difficult to perform adjustment to obtain desired results of the masking processes while changing the resistance values of the variable resistors, and that such a construction is improper for miniaturization. On the other hand, when the apparatus is moved, there is a possibility that the user might erroneously touch those variable resistors, requiring the user to adjust the levels again.
Further, the apparatus shown in FIG. 9 has a drawback that the masking operation circuit 59 needs a conversion ROM of a large capacity. For example, when each of the chrominance signals R, G and B has 256 gradations, if the output of the ROM consists of eight bits, a memory capacity of 256.times.256.times.3 bytes is necessary, so that this construction is improper for miniaturization. Moreover, since the mask data is written into an ordinary ROM (read only memory) or an EEPROM (electrically erasable and programmable read only memory), much labor is required to change masking constants and it is almost impossible for the general user to change those constants.
On the other hand, in the color correcting circuit as in image processing circuit in the apparatus shown in FIG. 8, a discrimination regarding whether the constants of the color correcting circuit are proper or not can be made only when reproducing the data received by the receiver after it had been once transmitted. Therefor, a long time is required and if the apparatus does not have any receiver, the adjustment for color correction can hardly be performed.
Although apparatus to display the result of the correction has already been known, even this apparatus cannot sufficiently indicate the contrast with the correcting agents.